Weakness and Dizziness Answers 389Myasthenia gravis (a)commonly presents with muscle weakness that is
exacerbated by activity, sleeplessness or alcohol intake and is relieved by rest.
The most frequent initial symptoms include ptosis, diplopia, and blurred vision.
Vertebrobasilar insufficiency (c)presents with cerebellar and brainstem symp-
toms, such as vertigo, dysphagia, and diplopia, none of which are present in
this patient. Encephalitis (d)is an infection of brain parenchyma and pre-
sents with altered mental status that may be associated with focal neurologic
deficits. Patients might present with behavioral and personality changes,
seizures, headache, photophobia, and generalized symptoms of fever, nausea,
and vomiting. Guillain-Barrésyndrome (e)is the most common polyneuropa-
thy. It is described as an ascending paralysis that is often preceded by a viral
syndrome. Classically it is associated with the loss of deep tendon reflexes.
353.The answer is e.(Rosen, pp 2553-2554.)Demyelinating MS lesions are
often well demonstrated on MRIbut cannot be visualized on (d)CT scan.
The edrophonium test (a)is used as an adjunct in the diagnosis of
myasthenia gravis. A carotid artery angiogram (b)is useful when evaluating
the carotid arteries for trauma, dissections, or thrombus. Analyzing CSF
(c)can help aid you in the diagnosis of MS as it often reveals oligoclonal band-
ing and elevated protein.
354.The answer is d.(Rosen, pp 1440-1442.)The patient is a good candidate
forfibrinolytic therapy.She is having an acute ischemic stroke(in the
distribution of the middle cerebral artery),has no contraindications to the
therapy and is being evaluated within the 3-hour (180-minute) therapeutic
window from the onset of symptoms. Exclusion criteria for the use of
thrombolytics include:
- Evidence of intracranial hemorrhage on noncontrast head CT (absolute)
- Minor or rapidly improving stroke symptoms
- Clinical suspicion for subarachnoid hemorrhage
- Active internal bleeding within last 21 days
- Known bleeding diathesis
- Within 3 months of serious head trauma, stroke, or intracranial surgery
- Within 14 days of major surgery or serious trauma
- Recent arterial puncture at noncompressible site
- LP within 7 days
- History of intracranial hemorrhage, A-V malformation
- Witnessed seizure at stroke onset
- Recent myocardial infarction, or systolic BP >185 mm Hg or diastolic BP >
110 mm Hg